[Excaliber]

Perform better doing what? Single four will out perform dual fours at an auto cross or a tight twisty road race event. Dual fours might be better for a hill climb depending on cornering involved. Dual fours will outperform a single at Le Mans on the long straight away. I'd take duals over a single at the drag strip. On the street, the dual fours or single, your call.

In general, assuming intake manifolds are similiar design, the dual fours will make more horse power than the single four, in my opinion.